Hypothesis
by broomclosetkink
Summary: Sherlolly scientific experiments exploring their relationship in any and all situation I (and my tumblr prompt givers) can think of. All range of rating, genre, and Sherlock being a completely brilliant moron.


**A/N: The first tumblr prompt to be finished and it's potterlock, and this one is set just before the end of the First War in 1981. Warning for angst and I'm not even sorry. **

**Disclaimer: I own neither Sherlock nor Harry Potter. (WHY GOD WHY?!)**

The sky is gunmetal gray with heavy, brooding clouds that threaten to split open and release another cold down pouring. Around Molly the muggle world is throbbing and flowing, so much faster and much more careless than what she's used to. She thought it would be calming to walk along the wet concrete and asphalt, to lose herself in the crowds, just an unassuming young woman that doesn't live in a world being torn apart by war. Instead the experience is claustrophobic, choking her with the weight of all she knows.

Hoisting her bag higher up on her shoulder, Molly follows the upward flow of the crowd. It's easy to move among them, like fish up stream, and easier still to slip onto a dirty side street. Her footsteps echo on brick and stone, and she makes a point of avoiding filmy puddles. Back out onto higher traffic areas and then she heads towards a corner pub that is passed by, eyes moving over it as though they can't see the wavy lead windows and the weathered sign that creaks in the wind.

The Leaky Cauldron is thankfully warm, which Molly is grateful for. With a heavy sigh she unwinds her scarf and pulls off her gloves, tucking them into an inside pocket of her cloak.

"Afternoon, Molls," greets Tom, the middle aged wizard that runs the Cauldron. "He's waiting for you upstairs."

"That's a first," she laughs, forcing back a cringe at the brittle sound. She remembers her first trip to the Cauldron as a little girl, clinging to her mother's hand and in awe; it was a place full of smoke, the heavy scents of good, hearty food, the chatter and laughter of patrons filling tables and corners and the bar. Now it's nearly empty, the few occupants keeping their heads down, taut fear in their shoulders and shivering fingers.

Tom mimics her laugh, hoarse and a bit desperate. "Just took a tray up, it should still be hot."

"Ta." Molly waves over her shoulder before mounting the treads, heading up the crooked, creaking staircase all the way to the second floor. The third door on the right is half open, the warm glow of a cheerfully burning fire spilling out in warm welcome and something inside her chest loosens. The door creaks as she makes her way inside, old hinges groaning when she closes it behind her and sets the lock into place. Withdrawing her wand, she taps it against the heavy iron, activating the wards placed on private rooms.

Tucking it away once more she removes her cloak and hangs it on a peg by the door. It looks plain and shabby by the heavier, more expensive one already residing there; the stitching is exquisite and it's clearly well-tailored, the frogs latching it ebony and silver. Molly can't resist running her hand across it as she turns, lifting her gaze to rest a worn but wholly pleased smile at the man she's come to meet.

"You're late," notes Sherlock, staring broodingly into the fire.

"You're early," she responds, moving across the room. There's a chair beside Sherlock's and she moves to it, sinking into the plush comfort of the ancient wingback. After toeing off her shoes she tucks the feet under her thighs, propping an elbow on the armchair before resting her chin in her hand. For a moment she takes in the weary frustration Sherlock tries so hard to keep hidden, wishing to seem impervious to the horrors of his work and the war. "You're tired," she gently observes.

Instead of bluffing or affecting outrage to cover up the truth of it, Sherlock gives a heavy sigh before reaching out. The space between their chairs is easily spanned, and his hand is warm and strong as he pulls Molly's hand down, slipping his fingers between hers and pressing their palms together. Another sigh, this one even more weighted than the first. "Yes," he admits, running his thumb over the rise of her knuckles.

She has no response to this, is too scared by the implications of Sherlock freely admitting to a weakness, even when it's only to her, in the privacy of a rented room. Because of this they're quiet, listening to the crackling fire and watching the hot embers as they fly up when a log snaps, its innards engulfed by flames.

Sherlock tugs, gesturing with his free hand. Molly follows the unspoken request, leaving the wingback to tuck herself against Sherlock's body, sitting crossways in his lap. He curls an arm over her back and rests his chin on the top of her head, a strangely fearful tremor shaking him.

"Would you do something for me, Molly?" She feels his words as much as she hears them, pressed against his chest as she is.

"Of course, Sherlock, anything; you know that."

"Do you mean it, Molly? Anything?"

Fear twists her gut into a knot. Molly's head lifts, her gaze searching the almost desperate face of the man her heart is so inexorably linked to. "What do you need?" There's a tightening of his mouth, a faint wobble to his chin; lifting a hand, he delicately touches the soft skin under her eyes, behind her ear, the throbbing pulse below her sharp jaw.

When Sherlock speaks his voice is hoarse, gravel scraping across concrete as he forces the words out. "I need you to leave, Molly."

She blinks once, uncomprehending. Her eyes narrow. "What?"

"Britain. It's not safe, Molly, and there's very little chance that Voldemort won't succeeding in winning this war."

"Don't say that!"

A fierce sort of desperation lights up Sherlock's eyes, searing Molly into a frozen silence. He takes a painful grip on her upper arms, breath moving hot and damp across her face as he speaks in a tight, rapid flow. "Don't be _stupid, _Molly, you're better than those blind idiots pretending we've still got a chance. Frank and Alice Longbottom were found yesterday, tortured absolutely around of their minds. Do you hear me? They're completely _mad, _Molly, just empty shells of what they used to be. Belletrix Lestrange, of course, it has all the markings of her sadism; Lestrade's beyond himself with rage but utterly impotent, bloody Anderson keeps going on about avenging their fallen comrades but if two of the best couldn't stand up to them what makes them think they can? It's only a matter of time, Molly. Do you understand? They're going after the strongest of the opposition: the Potters, Sirius, John and myself, Mad-Eye, McGonagall, eventually Dumbledore."

"But the Headmaster –"

"Is a mere mortal. If Voldemort attacks with his superior numbers, uses the giants to help him break into Hogwarts – what I'd do, if I were him, and while he's not quite as brilliant as I am he's still far too clever by half – Dumbledore will be slaughtered. Attack students, lure him out, he'll go like a lamb to be sacrificed. Mycroft is already making provisions."

Bile burns Molly's throat and tears sting her eyes, blurring Sherlock's face. One hand presses against her chest, as though to push away the horrid ache now residing there as she thinks of all the cruelty and horror devouring the world. Fingertips are a faint touch against her cheeks, brushing away tears when they begin to fall.

"I need you to leave." Never, in all their years of friendship and whatever this thing between them is now, never has Molly ever heard Sherlock beg; not when tortured by the Cruciatus, not when John was missing-in-action, not even when Molly had been caught in the attack on Diagon Alley and nearly died from a blood freezing hex. This, more than anything, sends blades of ice through her veins and very soul. "I couldn't – if it were you, Molly, I couldn't. I can't. I **_won't._**" His voice catches, breathless and choked.

The sight of tears brightening his fantastic eyes is more than Molly can bear. "I don't want to leave you," she admits, curling an arm around his neck. She's remembering a cold winter night in their seventh year, the too small bed and the way he cried out her name; the strange dance of concentric circles as they moved around each other afterward, Sherlock's stilted words ("I – I'm not – this can't – I'm not a _boyfriend, _do you see?"); his mouth, damp and fearful on her own in St. Mungo's while John looked on, incredulous, when she'd nearly died. Now she presses her face into his neck, takes a deep breath of his warm scent and holds it tight in her lungs for so long her head grows fuzzy and spots flicker across the back of her eyelids.

His hand on the back of her neck, trembling, a pained noise moving deep in his chest; these things provoke Molly into speaking. "I can't leave you here. If you died and I wasn't – oh Sherlock, no, I can't –"

"You'll be killed!"

"So will you!" Shifting around, Molly straddles Sherlock, her knees beside his sharp hips and her arms tight over his shoulders, caging him in. Pulling back just enough to give him a furious, tearful glare she practically vibrates from the force of her emotions. "I love you, Sherlock, and –"

"No, Molly, don't –" His hand lifts, tries to cover her mouth, to silence her, panic bright and clear in his eyes.

She slaps his hand away. "Damn it, Sherlock, _listen _to me! Just once in your life, please, _listen _instead of barreling over me because you don't want to hear what I have to say! I love you, you – you ignorant arse, and we've both known that since at least our seventh year. I've always stood beside you when you needed me, given what _you _needed, and I've been happy to do that because that's what you do when you love someone. You give, selflessly, without demands. Without regret. But I can't do this, Sherlock, I can't run away and leave you to die or – or worse. What if they – if it were you, if they took your mind, your beautiful –" A sob briefly ends the torrent of her words even as she cups his face in her hands, presses her forehead to his. Her tears fall on his cheeks, making paths for the ones he has yet to shed.

"If you stay, I stay. If you go, I'll go. But I won't leave you."

"Molly…" Swallowing hard, squeezing his eyes shut, Sherlock draws in a deep, shuddering breath, clearly trying to compose himself. "I am… unworthy of such devotion, and I couldn't – I won't see you harmed because of me." There's something else in his words, the reason for the breach between what they both want, the lapses in his control and the distance kept after.

When she speaks, Molly's voice is low and firm. "It's not up to you, Sherlock. It never has been. I've got my own mind, I make my own choices; I decide where I go and where I don't."

He brushes several strands of hair from her face, tucking them behind her ear with a pained smile. "Molly Hooper, will you never stop tormenting me?"

"Eventually you're going to learn to enjoy it."

Their laughter is too bright and false, striking the walls like brittle fists.

-X-

"You shouldn't have come here," Sherlock whispers against the inside of her wrist when they're inside his flat, already shedding clothing in a long trail to the bedroom. "They could be watching me."

"Then they saw us meeting."

"Friends meeting for our weekly visit, sometimes with John in tow or Lupin –"

"God, Sherlock, _shut up._"

His kiss tastes like salt and fearful desperation, and when it's over he presses his face into the mattress and weeps, quietly and deeply. Molly holds him through it, her head on his shoulder as she watches the shadows outside the window, wondering if one night one will come in and end it all.

-X-

It's late September, cold and rainy. St. Mungo's basement is too claustrophobic today and so despite the rain Molly takes a walk, hands in her pockets as she makes a slow circuit around the sad little neighborhood park. The trees are beginning to change, rusty leaves dripping rainwater.

"Molly!" John's voice is too loud, edged in hysteria. The rain seems to part around him, flying off his fast moving limbs as he runs towards her, sliding on the slick grass. "Molly, it's Sherlock!"

Turning her face into the rain she lets it soak her through, already too cold to feel it.


End file.
